Sowing seeds indoors during the winter months is a great way to get a head start on your spring and summer gardens. Knowing when your last frost date is will help you determine when to plant indoors and with the right mix and temperate of soil you will be successful in your growing endeavors.

Each type of plant differs on how early it should be planted indoors. Check the back of your seed packets for specific timeframe for that particular type of seed. Below is a general timeframe for vegetables and flowers, listing how many weeks before the last frost date to start your seeds and how long the germination period should be.

Vegetables

Vegetable

Start Seeds Indoors (# Weeks Before Last Frost Date)

Germination Period (Days)

Beans

4 to 6

7 to 14

Beets

5 to 6

10 to 14

Broccoli

8 to 10

5 to 10

Cabbage

8 to 10

5 to 10

Cauliflower

8 to 10

5 to 10

Cucumbers

3 to 4

4 to 10

Eggplant

7 to 8

5 to 14

Lettuce

8 to 10

3 to 10

Onions

8 to 15

10 to 14

Peas

1 to 2

14 to 20

Peppers

7 to 8

5 to 14

Pumpkins

3 to 4

7 to 10

Squash

3 to 4

4 to 10

Sweet Corn

2 to 3

5 to 7

Tomatoes

6 to 7

5 to 10

Flowers

Begonias

12 to 14

10 to 15

Pansies

12 to 14

6 to 10

Impatients

10 to 11

15 to 18

Petunias

10 to 11

6 to 10

Marigolds

6 to 7

5 to 8

Snapdragon

9 to 10

6 to 12

Geraniums

12 to 15

10 to 20

Phlox

8 to 9

5 to 10

Before Planting make sure your seeds are planted in a fresh soil mix, clean containers and don't forget to label your seeds. Before planting sort your seeds by germination temperature and plant similar temperatures together, but stick to one to two varieties per tray. When selecting the number of plants you want to plant, double that amount to factor in success rate. A rule of thumb for seed planting is 50 square inches of soil will house up to 50 large seeds, 100 small seeds and 5,000 tiny seeds.

A good way to get the right amount of moisture in your soil before planting is to put one cup of water to every four cups of soil you are planning on using into a plastic bag. Then squeeze the bag to mix so the water absorbs into the soil. Once you have a good mixture fill the trays 3/4 full.

TIP: Use the eraser end of a pencil to create indents into the soil about a 1/4 inch. For tiny seeds only indent 1/8 inch and medium size seeds can be pushed into the soil.

For seeds that need to be covered with soil to germinate, they should be covered with twice their thickness of soil. Seeds that do need light to germinate should not be covered. Check the back of your seed packet to determine which seeds should be covered and which should not. Once seeds are planted place containers into a tray of shallow water to keep soil moist and to avoid seeds from being washed away from watering the top of the soil. Make sure the water is room temperature and cover with plastic wrap. Most seeds like to germinate in temperatures of about 65 to 75 degrees Fahrenheit.
Once your seeds are planted, you can sit back and watch your plants grow. Just remember to keep an eye on soil moisture and make sure your plants have adequate sunlight. If you are planning on transplanting to your garden in the spring or summer, make sure you harden them to get used to outdoor conditions. One week before you are planning on transplanting, place your seedlings outdoors for a few hours the first day then gradually increase each day.